Hypertension/blood pressure affects millions of people each year. Blood pressure is measured with a blood pressure cuff and recorded as two numbers, such as 120/80 mm Hg (millimeters of mercury).    A top, larger number is called a systolic pressure. This is pressure generated when heart contracts (pumps). It reflects the pressure of the blood against arterial walls.    A bottom, smaller number is called a diastolic pressure. This reflects the pressure in the arteries while the heart is filling and resting between heartbeats.
When hypertension/high blood pressure is left untreated, it may lead to heart disease, heart attack, congestive heart failure, stroke, kidney failure, peripheral artery disease, and aortic aneurysms (outpouchings of the aorta).
There are six primary classes of antihypertensive drugs: Thiazide or thiazidelike diuretics act on the kidneys to help rid the body of salt and water through urination. With less fluid in the body, blood volume goes down, which results in a fall in blood pressure. Adverse effects of thiazide diuretics include sexual dysfunction, glucose intolerance, gout, low potassium level (hypokalemia), and low sodium level (hyponatremia). Beta blockers: these drugs may worsen blood glucose control, elevate triglyceride level, and lower high-density lipoprotein (HDL—sometimes called the “good” cholesterol). Angiotensin II receptor blockers (ARBs) work similarly to ACE inhibitors. Adverse effects of ARBs can include headache, drowsiness, diarrhea, and a metallic or salty taste in the mouth. Calcium channel blockers (CCBs) affect a transport of calcium into the cells of the heart and blood vessels, causing blood vessels to relax. Adverse effects of CCBs include constipation, swelling of the lower part of the legs, flushing, or headache. Alpha blockers block alpha receptors in vascular smooth muscle, preventing the uptake of catecholamines, which are produced in response to stress. People using alpha blockers may experience a drop in blood pressure (called orthostatic hypotension) when they go from sitting or lying down to standing. Other common adverse effects include stuffy nose and dizziness.